Lubrication devices for gear trains in wind power stations are known and readily available on the market. In the manner of closed circulating lubrication, the lubricant, especially in the form of lubricating oil, is removed by gear oil pumps from the gear sump of the gear housing with the gear stages, supplied to filtering by the filter unit, for filtering, and discharged again to the interior of the gear housing to remove fouling, including in the form of metal shavings, from the lubricant. In spite of these measures, premature damage to the gears, which often occurs after six months, takes place in practical applications, both within the planet stage and on the spur wheel stage generally forming the two gear stages for the rotor of a wind power station. In particular, the planet stage often fails due to defective planet bearings, as do the gear oil pumps of wind power stations due to metal shavings which occur with increased frequency in the lubricant circuit. The reason for such failures is that within the spur wheel stage, due to the formation of resting zones with large areas for the lubricant (oil), it becomes possible for heavy metal particles to settle in those resting zones. Often lubricant or oil exchange takes place only in the area of the spur wheel stage so that lubricant exchange takes place only conditionally, and contaminated or dirty lubricant can remain on the sides of the planet stage and can cause damage there.